Abstract
FePt has drawn lots of attention for the next-generation perpendicular magnetic recording media because of its large magnetocrystalline anisotropy. For L10 FePt-based granular recording media, the desired granular structure can be achieved by the addition of boron. However, the residual boron in FePt grains retards the L10 ordering. In first part, we introduce an additional post-annealing process in the oxygen atmosphere after the deposition of FePt:B films. We show that oxygen is capable of improving the boron segregation and therefore yields the granular and L10 ordered FePt films with the (001) orientation. In the other hand, C addition was reported as a promising segregant to obtain a small grain size of 6 nm with good L10 ordering and (001)-oriented FePt grains.However, the segregation on the top of FePt leads to a second layer of FePt grains with (111) orientation. In second part, we used bilayer composed of FePt:B (30 vol. %) and FePt:C (28 vol. %) films to take advantage of two segregants.By optimizing thickness of FePt:C and FePt:B we gets a good isolated granular structure with promoted columnar growth grain of 6.92 nm and aspect of 1.44 . We shows that the FePt:C template layer is able to retrieve the ordering in FePt:B by forming the B-C phase which is investigated by Synchrotron Radiation XPS.